/**
 * Copyright (C) 2002-2015   The FreeCol Team
 * <p>
 * This file is part of FreeCol.
 * <p>
 * FreeCol is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 * <p>
 * FreeCol is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with FreeCol.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.sf.freecol.common.model;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.xml.stream.XMLStreamException;

import net.sf.freecol.common.io.FreeColXMLReader;
import net.sf.freecol.common.io.FreeColXMLWriter;


/**
 * Represents one of the European nations present in the game,
 * i.e. both REFs and possible human players.
 */
public class EuropeanNationType extends NationType
{

    /** Whether this is an REF Nation. */
    private boolean ref = false;

    /**
     * Stores the starting units of this Nation at various
     * difficulties.
     */
    private final Map< String, Map< String, AbstractUnit > > startingUnitMap = new HashMap<>( );


    /**
     * Create a new European nation type.
     *
     * @param id The object identifier.
     * @param specification The <code>Specification</code> to refer to.
     */
    public EuropeanNationType( String id, Specification specification )
    {
        super( id, specification );
    }


    /**
     * Is this a REF nation type?
     *
     * @return True if this is a REF nation type.
     */
    @Override
    public final boolean isREF( )
    {
        return ref;
    }

    /**
     * Is this a European nation type?
     *
     * @return True.
     */
    @Override
    public boolean isEuropean( )
    {
        return true;
    }

    /**
     * Is this a native nation type?
     *
     * @return False.
     */
    @Override
    public boolean isIndian( )
    {
        return false;
    }

    /**
     * Gets the starting units for this nation type.
     *
     * @return A list of <code>AbstractUnit</code>s to start with.
     */
    public List< AbstractUnit > getStartingUnits( )
    {
        boolean ex = getSpecification( ).getBoolean( GameOptions.EXPERT_STARTING_UNITS );
        return getStartingUnits( String.valueOf( ex ) );
    }

    /**
     * Gets a list of this Nation's starting units at the given
     * difficulty.
     *
     * @param key The value of the expert-starting-units field.
     * @return A list of <code>AbstractUnit</code>s to start with.
     */
    public List< AbstractUnit > getStartingUnits( String key )
    {
        Map< String, AbstractUnit > result = new HashMap<>( );
        Map< String, AbstractUnit > defaultMap = startingUnitMap.get( null );
        Map< String, AbstractUnit > difficultyMap = startingUnitMap.get( key );
        if ( defaultMap != null )
        {
            result.putAll( defaultMap );
        }
        if ( difficultyMap != null )
        {
            result.putAll( difficultyMap );
        }
        return new ArrayList<>( result.values( ) );
    }

    /**
     * Add a starting unit.
     *
     * @param id The unit identifier.
     * @param unit The <code>AbstractUnit</code> to add.
     * @param expert Is this an expert unit?
     */
    private void addStartingUnit( String id, AbstractUnit unit, boolean expert )
    {
        String exTag = ( expert ) ? Boolean.TRUE.toString( ) : null;
        Map< String, AbstractUnit > units = startingUnitMap.get( exTag );
        if ( units == null )
        {
            units = new HashMap<>( );
            startingUnitMap.put( exTag, units );
        }
        units.put( id, unit );
    }


    // Serialization

    private static final String EXPERT_STARTING_UNITS_TAG = "expert-starting-units";
    private static final String REF_TAG = "ref";
    private static final String ROLE_TAG = "role";
    private static final String TYPE_TAG = "type";
    private static final String UNIT_TAG = "unit";


    /**
     * {@inheritDoc}
     */
    @Override
    protected void writeAttributes( FreeColXMLWriter xw ) throws XMLStreamException
    {
        super.writeAttributes( xw );

        xw.writeAttribute( REF_TAG, ref );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void writeChildren( FreeColXMLWriter xw ) throws XMLStreamException
    {
        super.writeChildren( xw );

        if ( startingUnitMap != null && ! startingUnitMap.isEmpty( ) )
        {
            Map< String, AbstractUnit > map;
            // default map
            if ( ( map = startingUnitMap.get( null ) ) != null )
            {
                for ( Map.Entry< String, AbstractUnit > entry : map.entrySet( ) )
                {
                    writeUnit( xw, entry.getKey( ), entry.getValue( ), false );
                }
            }
            // expert map
            if ( ( map = startingUnitMap.get( Boolean.TRUE.toString( ) ) ) != null )
            {
                for ( Map.Entry< String, AbstractUnit > entry : map.entrySet( ) )
                {
                    writeUnit( xw, entry.getKey( ), entry.getValue( ), true );
                }
            }
        }
    }

    private void writeUnit( FreeColXMLWriter xw, String id,
                            AbstractUnit au,
                            boolean expert ) throws XMLStreamException
    {
        xw.writeStartElement( UNIT_TAG );

        xw.writeAttribute( ID_ATTRIBUTE_TAG, id );

        xw.writeAttribute( TYPE_TAG, au );

        xw.writeAttribute( ROLE_TAG, au.getRoleId( ) );

        //xw.writeAttribute("number", unit.getNumber());

        if ( expert ) xw.writeAttribute( EXPERT_STARTING_UNITS_TAG, expert );

        xw.writeEndElement( );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void readAttributes( FreeColXMLReader xr ) throws XMLStreamException
    {
        super.readAttributes( xr );

        final Specification spec = getSpecification( );

        EuropeanNationType parent = xr.getType( spec, EXTENDS_TAG,
                                                EuropeanNationType.class, this );

        ref = xr.getAttribute( REF_TAG, parent.ref );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void readChildren( FreeColXMLReader xr ) throws XMLStreamException
    {
        // Clear containers.
        if ( xr.shouldClearContainers( ) )
        {
            startingUnitMap.clear( );
        }

        final Specification spec = getSpecification( );
        EuropeanNationType parent = xr.getType( spec, EXTENDS_TAG,
                                                EuropeanNationType.class, this );
        if ( parent != this )
        {
            for ( Map.Entry< String, Map< String, AbstractUnit > > entry
                    : parent.startingUnitMap.entrySet( ) )
            {
                startingUnitMap.put( entry.getKey( ), new HashMap<>( entry.getValue( ) ) );
            }
        }

        super.readChildren( xr );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void readChild( FreeColXMLReader xr ) throws XMLStreamException
    {
        final String tag = xr.getLocalName( );

        if ( UNIT_TAG.equals( tag ) )
        {
            String id = xr.readId( );

            String type = xr.getAttribute( TYPE_TAG, ( String ) null );

            String roleId = xr.getAttribute( ROLE_TAG,
                                             Specification.DEFAULT_ROLE_ID );

            // @compat 0.10.7
            roleId = Role.fixRoleId( roleId );
            // end @compat

            boolean ex = xr.getAttribute( EXPERT_STARTING_UNITS_TAG, false );

            addStartingUnit( id, new AbstractUnit( type, roleId, 1 ), ex );
            xr.closeTag( UNIT_TAG );

        }
        else
        {
            super.readChild( xr );
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getXMLTagName( ) { return getXMLElementTagName( ); }

    /**
     * Gets the tag name of the root element representing this object.
     *
     * @return "european-nation-type".
     */
    public static String getXMLElementTagName( )
    {
        return "european-nation-type";
    }
}
